Re: Vizio M70-C3 diagnosis
Well, kind of a kick in the balls. I hadn't given the screen a good look after changing the main board, and I had never seen this TV working prior do the board going out. Looks like it also has some half failed LED strips. I swapped some of the backlight power ribbon cables around and the dim spots remained in the same locations so I think it's just the LEDs and the driver is fine.
On the fence as to whether fixing it at this point is worth it or not....
objext
Member
Last Activity: 05-15-2023, 09:08 PM
Joined: 04-23-2023
Location: Carl Junction, MO
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Re: Vizio M70-C3 diagnosis
The seller only had the one board...looked like he was parting out one TV.
Here's the one I bought and the one I replaced. The seller included the heatsink & heat pipe with the board. I just meant that I will take it off and replace the thermal compound & reinstall since it's likely old & dry and I have quality thermal compound on hand....Leave a comment:
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Re: Vizio M70-C3 diagnosis
Finally got around to trying the ebay board. TV is working with the replacement main board. Going to pull the heatsink and replace the thermal compound before I button everything back up.Leave a comment:
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Re: Vizio M70-C3 diagnosis
Going to try out a "tested" mainboard from ebay. I'll report back when I get it and swap it in.Leave a comment:
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Re: Vizio M70-C3 diagnosis
BGA is ball grid array. Instead of pins, the chip uses an array of solder balls to make connection to an array or flat solder pads on the circuit board. Basically a surface mount chip solder sandwich. Heat, flex, and lead free solder can lead to the balls cracking...Leave a comment:
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Re: Vizio M70-C3 diagnosis
Thanks, I had watched those related videos but none touch exactly on the case where I get standby power and turn-on, etc, but no video. I would not be surprised if a surge took out the main board. I replaced the mainboard in my in-law's TV twice after electrical storms. A lightning surge took out the hdmi ports so I replaced the board, and then a second storm rolled through and took it out again less than a week later. Finally got it on surge protection and no problems since....Leave a comment:
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Re: Vizio M70-C3 diagnosis
I did try hot air but without removing the heatsink. Will the studs pop out without pulling the board? Otherwise, sounds like a main board issue, yeah?Leave a comment:
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Re: Vizio M70-C3 diagnosis
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4
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0.43
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12.7
12.7
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This doesn't surprise me because it can't be powered on without the main board.Leave a comment:
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Re: Vizio M70-C3 diagnosis
No smell of burning...Leave a comment:
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Re: Vizio M70-C3 diagnosis
Also nothing on this tcon connector. I do get PS-ON signal, etc. Power supply seems to be working (?). Have tried pressing on main board heatsink, but no change....Leave a comment:
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Re: Vizio M70-C3 diagnosis
Updating the firmware doesn't require anything to be seen on-screen?...Leave a comment:
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Re: Vizio M70-C3 diagnosis
Hate to sound helpless, but their page doesn't work. After I enter the s/n (LFTRSYAR3002382), it takes me to a page that says
...but when you click for more information it takes you to an invalid page....Leave a comment:
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Re: Vizio M70-C3 diagnosis
Tcon fuse checks out ok...Leave a comment:
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Re: Vizio M70-C3 diagnosis
How about these...Leave a comment:
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Vizio M70-C3 diagnosis
Hi all, I have an M70-C3 Vizio that won't power on. I do get power/standby LED and optical output operation. I don't seem to have backlighting or display image, or sound.
I have negligible voltage (0.001-0.003V) at T CON_ON and both 12V T CON pins.
I have 12V on both +12VS pins.
I have 33.xxV on 24V1 pins.
TV was working before a thunderstorm, but I'm not 100% sure that's why it quit. I tried to record how the standby LED functions in the attached list. What should I look at? Power supply caps appear okay. Thanks!... -
Re: New Members - please post your introductions here
Hi, I'm Matt. Usually I work on old school car audio (RF mainly), but occasionally pick up newer electronics to attempt repairs.Leave a comment:
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